[Why]
Start using INBOX0 for HW Lock command

[How]
- Implement initial interface for INBOX0 HW lock message
Signed-off-by: NAlvin Lee <Alvin.Lee2@amd.com>
Reviewed-by: NJun Lei <Jun.Lei@amd.com>
Acked-by: NQingqing Zhuo <qingqing.zhuo@amd.com>
Tested-by: NDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>